Rotary engines



Sept. 15 1964 L. PERAS 3,148,667

ROTARY ENGINES Filed Jude 8, 1961 INVENT OR Lumen PERAs BYM ATTORNEYS United States Patent f 3,148,667 ROTARY ENGINES Lucien Pras, Billancourt, France, assignor to Regie Nationale ties Usines Renault, Billancourt, France Filed June 8, 1961, Ser. No. 115,657 Claims priority, application France, July 5, 1960, 832,126, Patent 1,272,529 1 Claim. (Cl. 123-8) This invention relates to a rotary engine consisting on the one hand of a rotor having a contour in the form of a two-arc shortened epicycloid and on the other hand of a stator consisting of three lobes separated by three sealing strips constantly engaging the rotor contour to which an eccentric movement of rotation is imparted.

This engine thus comprises three variable-volume Working chambers bound respectively by each of the stationary lobes of the stator and by the rotor contours of which the displacements are set by the eccentricity of the engine shaft.

It is known to provide inlet and exhaust ports for these chambers; besides, it has already been proposed, in connection with other types of rotary engines, to use valves actuated as a function of the velocity of rotation of the engine. This invention is concerned with an engine of the type set forth hereinabove wherein the inlet and exhaust valves are associated With constant-volume combustion chambers having a compact structure consistent with the best combustion conditions for the detonating mixture.

More particularly, this invention is concerned with a specific form of embodiment of an engine of this type wherein the constant-Volume combustion chambers are formed in the side walls of the stator and receive valves having their axes inclined in relation to the engine axis, the spark plug being located in the vicinity of these valves.

On the other hand, the inlet and exhaust valves are advantageously actuated through rockers of which the opening and closing diagram can be adjusted at will with a view to obtain the optimum efiiciency and assist in improving the fiexibility of operation as Well as the idling conditions of the engine.

Due to the inclined position of the valves in each chamber in relation to the engine axis and to their relative position, a so-called roof-shaped combustion chamber promoting an efiicient fuel combustion can be constructed.

The invention will now be described with reference to the accompanying drawings illustrating diagrammatically by way of example a typical form of embodiment of the invention. In the drawings:

FIGURE l'is an axial section showing the engine constituting the subject-matter of this invention, and

FIGURE 2 is an end view of the rotor and stator as sembly, showing the arrangement of the working chambers, the positions of the valves and of the radial fixed sealing strips between the stator and rotor.

Referring toFIG. 1, the reference numeral 1 designates the two-arc epicycloid rotor rotatably mounted in a stator 2 comprising three lobes separated by radial sealing strips 27. The rotor 1 is mounted in overhanging relationship on an eccentric pin 3 rigid with an engine or driving shaft 4. Toothed wheels 25 and 25' rigid with the rotor 1 revolve eccentrically and are in meshing engagement with internally toother gears 26, 26' fixedly mounted on the stator 2. A combustion-head 5 of substantially circular r. CC

, configuration carries the combustion chambers proper 6,

the inlet and exhaust valves 7, 8 and the spark plugs 9. The flange 10 of this combustion-head 5 closes the stator and access to the rotor may be had therethrough. The combustion chambers 6 have a substantially compact shape depending on the valve dimensions and on the compression ratio; with this so-called roof shape it is possible to reduce the area of the combustion chamber to a minimum; each chamber communicates with a variablevolume working chamber 11 formed by the stator and rotor. The inlet valves 7 and exhaust valves 8 open directly into these chambers and extend radially with an inclination of about 120.

These valves are controlled by means of a tubular camshaft 12 having one cam race 13 for the inlet and another cam race 14 for the exhaust, these cam races actuating push-rods such as 15 guided for axial movement in bores formed in bosses 16 of the combustion head.

Valve rockers 17 fulcrumed on pins 18 are responsive to the cam races through the push-rods and engage the outer end of the valve shanks, for example through known devices for adjusting the valve clearance, the valves themselves being urged by spring means to their seated position as in conventional valve disposals.

The tubular camshaft 12 is rotatably driven in any suitable manner from the engine shaft 4, for example through the medium of a gearing providing a suitable ratio, but any other suitable and known driving arrangement may be resorted to, for example a linkage system,

without departing from the spirit and scope of the in- Vention.

Although the present invention has been described in conjunction with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and appended claims.

I claim:

A rotary engine comprising a rotor having a two-arc shortened epicycloid contour and a stator having three lobes, sealing strips separating said three lobes and constantly engaging the rotor contour, said engine comprising, associated with each of the three working chambers constituted in the lobes between the stator and the rotor, a combustion chamber of constant volume formed in the side of said stator, a pair of valves and a sparkplug opening into said chamber, said chamber having a triangular form in axial section, the faces of which, being inclined one on the other and opening on said side of the stator, one of said faces receiving the valves, a cam race in the axis of the stator shaft and driven thereby, members cooperating with said race to control the lifting of the valves, the axis of which extends in an angle of about with the axis of the engine, and a sparkplug opening on the face of the combustion chamber that is opposite to that receiving the valves.

References Cited in the file of this patent UNITED STATES PATENTS Patented Sept. 15, 1964" 

